Brad Pitt, Angelina Jolie hit 'World War Z' premiere post-surgery

Nardine Saad

Angelina Jolie stepped out for the first time since revealing that she underwent a preventative double mastectomy. The superstar hit the London premiere of fiance Brad Pitt's action flick "World War Z"looking happy and healthy as she spoke about her condition.

Jolie underwent three months of medical procedures to remove both breasts and decrease her high risk of breast cancer. She later had reconstructive surgery to have them replaced on April 27. She plans to have her ovaries removed next. She first made the announcement in May with an op-ed in the New York Times. And on Saturday she had her first public appearance, wearing a back-baring black Saint Laurent gown, at the film's premiere at the Empire Cinema in London.

"I've been very happy just to see the discussion about women's health expanded, and that means the world to me," Jolie said at the premiere. "And after losing my mom to these issues I'm very grateful for it, and I've been very moved by the kind support from people, really very grateful for it."

Pitt, whose children range from ages 4 to 11, added that their family has a "no secrets" policy.

"I mean, there's an age of understanding, so you've got to present it in a way that is age-appropriate, but we know our children very well. We want everything to be on the table and any questions they have, for them to ask." he said.

The pair also walked the black carpet for the film again on Monday at Cinema UGC Normandie in Paris, France.

"World War Z," in which Pitt plays ex-U.N. investigator Gerry Lane, who races around the world trying to figure out the origin of a disease that appears poised to wipe out mankind, opens June 21.